Devices, systems, and methods for cooling a surgical instrument

ABSTRACT

A surgical system includes a surgical instrument and a cooling module. The cooling module includes a fluid reservoir retaining a conductive cooling fluid, a pump configured to pump the conductive cooling fluid along a flowpath, first and second electrodes disposed at first and second positions along the flowpath and configured to sense an electrical property of the conductive cooling fluid at the first and second positions, and a controller configured to determine an impedance of the conductive cooling fluid between the first and second positions based upon the sensed electrical properties of the first and second electrodes. A method for cooling a surgical instrument includes detecting an electrical property of a conductive cooling fluid at first and second positions along a flowpath and determining an impedance of the conductive cooling fluid between the first and second positions based upon the detected electrical properties at the first and second positions.

BACKGROUND Technical Field

The present disclosure relates to devices, systems, and methods forcooling a surgical instrument and, in particular, to devices, systems,and methods for cooling a surgical instrument and systems and methodsfor controlling the same.

Background of Related Art

Energy-based tissue treatment is well known in the art. Various types ofenergy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal,laser, etc.) are applied to tissue to achieve a desired result.Ultrasonic energy, for example, may be delivered to tissue to treat,e.g., coagulate and/or cut, tissue.

Ultrasonic surgical instruments, for example, typically include awaveguide having a transducer coupled thereto at a proximal end of thewaveguide and an end effector disposed at a distal end of the waveguide.The waveguide transmits ultrasonic energy produced by the transducer tothe end effector for treating tissue at the end effector. The endeffector may include a blade, hook, ball, shears, etc., and/or otherfeatures such as one or more jaws for grasping or manipulating tissue.During use, the waveguide and/or end effector of an ultrasonic surgicalinstrument can reach temperatures greater than 200° C.

It would therefore be desirable to provide devices, systems, and methodsfor cooling a surgical instrument and controlling cooling of the same.

SUMMARY

As used herein, the term “distal” refers to the portion that is beingdescribed which is further from a user, while the term “proximal” refersto the portion that is being described which is closer to a user.Further, to the extent consistent, any of the aspects described hereinmay be used in conjunction with any or all of the other aspectsdescribed herein.

A surgical system provided in accordance with aspects of the presentdisclosure includes a surgical instrument defining an input and anoutput, and a cooling module operably coupled to the input and output ofthe surgical instrument. The cooling module includes a fluid reservoirretaining a conductive cooling fluid, a pump assembly, first and secondelectrodes, and a controller. The pump assembly is operably coupled tothe fluid reservoir and configured to pump the conductive cooling fluidalong a flowpath from the fluid reservoir, into the input of thesurgical instrument, through at least a portion of the surgicalinstrument, out the output of the surgical instrument, and back to thefluid reservoir. The first and second electrodes are disposed at firstand second spaced-apart positions along the flowpath and are configuredto sense an electrical property of the conductive cooling fluid at thefirst and second positions. The controller is configured to determine animpedance of the conductive cooling fluid between the first and secondpositions based upon the sensed electrical properties of the first andsecond electrodes.

In an aspect of the present disclosure, the surgical instrument includesan ultrasonic waveguide having a blade defined at the distal endthereof. In such aspects, the flowpath may extend at least partiallythrough the blade. The surgical instrument may further include anultrasonic transducer coupled to the ultrasonic waveguide and configuredto energize the blade for treating tissue therewith.

In another aspect of the present disclosure, the surgical system furtherincludes a generator configured to supply energy to the surgicalinstrument. The generator may be disposed on the surgical instrument ormay be spaced-apart therefrom.

In yet another aspect of the present disclosure, the surgical instrumentfurther includes an activation button operably coupled to the generatorand including a first activated position and a second activated positionfor activating the surgical instrument in a first mode and a secondmode. In such aspects, the first and second electrodes may be operablycoupled to the generator through the activation button.

In still another aspect of the present disclosure, the first position isdisposed adjacent a distal end of the surgical instrument and/or thesecond position is disposed adjacent the cooling module.

In still yet another aspect of the present disclosure, the controller isconfigured to determine a temperature of the surgical instrument basedupon the determined impedance. Additionally or alternatively, thecontroller is configured to determine whether the flowpath has beenproperly primed with the conductive cooling fluid based upon thedetermined impedance. Additionally or alternatively, the controller isconfigured to at least one of start or stop the pump assembly based uponthe determined impedance. Additionally or alternatively, the controlleris configured to control the pump assembly based upon the determinedimpedance. Additionally or alternatively, the controller is configuredto determine the presence of at least one of air bubbles, a blockage, ormechanical damage to the surgical instrument based upon the determinedimpedance.

In another aspect of the present disclosure, the cooling module isdisposed on the surgical instrument. Alternatively, the cooling modulemay be spaced-apart from the surgical instrument.

A method for cooling a surgical instrument provided in accordance withaspects of the present disclosure includes detecting an electricalproperty of a conductive cooling fluid at a first position along aflowpath from a fluid reservoir, into an input of a surgical instrument,through at least a portion of the surgical instrument, out an output ofthe surgical instrument, and back to the fluid reservoir. The methodfurther includes detecting an electrical property of the conductivecooling fluid at a second position along the flowpath and determining animpedance of the conductive cooling fluid between the first and secondpositions based upon the detected electrical properties at the first andsecond positions.

In an aspect of the present disclosure, the method further includesdetermining whether the flowpath has been properly primed with theconductive cooling fluid based upon the determined impedance.Additionally or alternatively, the method may further include at leastone of initiating or stopping flow of the conductive fluid along theflowpath based upon the determined impedance. Additionally oralternatively, the method may further include determining at least oneof air bubbles, a blockage, or mechanical damage to the surgicalinstrument based upon the determined impedance.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects and features of the present disclosure are describedhereinbelow with reference to the drawings wherein like numeralsdesignate identical or corresponding elements in each of the severalviews:

FIG. 1 is a perspective view of a surgical system provided in accordancewith the present disclosure including an endoscopic ultrasonic surgicalinstrument, a cooling module, and a cooling system incorporated therein;

FIG. 2A is an enlarged, perspective view of the area of detail indicatedas “2A” in FIG. 1;

FIG. 2B is an enlarged, perspective view of the area of detail indicatesas “2B” in FIG. 1;

FIG. 3 is an enlarged, perspective view of the distal end of thesurgical instrument of FIG. 1;

FIG. 4 is a schematic illustration of the surgical system of FIG. 1depicting the internal operating components of the cooling systemthereof;

FIG. 5 is an exploded, perspective view of another surgical systemprovided in accordance with the present disclosure including a handheldendoscopic ultrasonic surgical instrument ultrasonic surgical instrumentincluding an on-board cooling module and having a cooling systemincorporated therein;

FIG. 6 is a side, cross-sectional view of an open ultrasonic surgicalinstrument provided in accordance with the present disclosure andincluding a cooling system configured for use therewith;

FIG. 7 is an enlarged, top, cross-sectional view of the blade of thesurgical instrument of FIG. 6;

FIG. 8A is an enlarged, side, cross-sectional view of a portion of thesurgical instrument of FIG. 6, illustrating routing of the coolingconduits into and through the waveguide of the surgical instrument;

FIG. 8B is a greatly enlarged, side, cross-sectional view of a portionof the surgical instrument of FIG. 6, illustrating the routing of thecooling conduits through the waveguide of the surgical instrument;

FIG. 9 is an enlarged, side view illustrating coupling of the coolingconduits of the surgical instrument of FIG. 6 with a tube splitter ofthe surgical instrument to enable the supply and return of cooling fluidfrom the surgical instrument;

FIG. 10A is a flow diagram depicting a method of cooling a surgicalinstrument provided in accordance with the present disclosure;

FIG. 10B is a flow diagram depicting another method of cooling asurgical instrument provided in accordance with the present disclosure;and

FIG. 11 is a schematic illustrating of another cooling system providedin accordance with the present disclosure, depicting the internaloperating components of the cooling system.

DETAILED DESCRIPTION

FIG. 1 depicts a surgical system 10 provided in accordance with theaspects and features of the present disclosure. Surgical system 10generally includes an endoscopic ultrasonic surgical instrument 100 anda base unit 500 that, together, incorporate a cooling system for coolinga blade 162 of an end effector assembly 160 of endoscopic ultrasonicsurgical instrument 100. Although detailed hereinbelow with respect tosurgical system 10 and, more particularly, endoscopic ultrasonicsurgical instrument 100 and cooling module 500 thereof, the aspects andfeatures of the present disclosure are equally applicable for use withany other suitable surgical system, surgical instrument, and/or coolingmodule incorporating a cooling system. For example, the aspects andfeatures may be provided for use in connection with a surgical system 20including an endoscopic ultrasonic surgical instrument 1100incorporating a cooling module 1500 thereon (see FIG. 5). Further still,another surgical instrument provided in accordance with the presentdisclosure, open ultrasonic surgical instrument 2100 (FIGS. 6-9), maysimilarly incorporate the aspects and features of the presentdisclosure. Obviously, different considerations apply to each particulartype of system, instrument, and/or unit; however, the aspects andfeatures of the present disclosure are equally applicable and remaingenerally consistent with respect to any such system, instrument, and/orunit.

Continuing with reference to FIG. 1, endoscopic ultrasonic surgicalinstrument 100 generally includes a disposable 102, a transducer andgenerator assembly (“TAG”) 200 including a transducer 210 and agenerator 220 (FIG. 4), a battery 300, and a cable 400. Disposable 102includes a housing 110, a handle assembly 120, a rotating assembly 130,an activation button 140, an elongated body portion 150, and endeffector assembly 160. TAG 200 and battery 300 are releasably engagablewith housing 110 of disposable 102 and, when engaged therewith, aredisposed in electrical communication with one another such that powerand/or control signals can be relayed between TAG 200 and battery 300for operating instrument 100. TAG 200 may further include an indicator202 disposed thereon, which will be described in greater detail below.

Elongated body portion 150 of disposable 102 of instrument 100 includesa waveguide 152 which extends from housing 110 to end effector assembly160, an outer tube 154, and an inner tube (not shown). The distal end ofwaveguide 152 extends distally from outer tube 154 and defines blade 162of end effector assembly 160, while the proximal end of waveguide 152 isoperably coupled to TAG 200. Outer tube 154 is slidably disposed aboutwaveguide 152 and extends between housing 110 and end effector assembly160. Rotating assembly 130 is rotatably mounted on housing 110 andoperably coupled to elongated body portion 150 so as to enable rotationof elongated body portion 150 and end effector assembly 160 relative tohousing 110.

End effector assembly 160 is disposed at a distal end of elongated bodyportion 150 and includes blade 162 and a jaw member 164. Jaw member 164is pivotable relative to blade 162 between an open position, wherein jawmember 164 is spaced-apart from blade 162, and a closed position,wherein jaw member 164 is approximated relative to blade 162 injuxtaposed alignment therewith for clamping tissue therebetween. Jawmember 164 is operably coupled to the distal end of outer tube 154 andthe proximal end of outer tube 154 is operably coupled to movable handle122 of a handle assembly 120, such that jaw member 164 is movablebetween the open position and the closed position in response toactuation of movable handle 122 of handle assembly 120 relative to fixedhandle portion 124 thereof.

Blade 162 is configured to serve as an active or oscillating ultrasonicmember that is selectively activatable to ultrasonically treat tissuegrasped between blade 162 and jaw member 164. TAG 200 is configured toconvert electrical energy provided by battery 300 into mechanical energythat is transmitted along waveguide 152 to blade 162. More specifically,TAG 200 is configured to convert the electrical energy provided bybattery 300 into a high voltage alternating current (AC) waveform thatdrives the transducer (not shown) of TAG 200. Activation button 140 isdisposed on housing 110 of disposable 102 and is electrically coupledbetween battery 300 and TAG 200. Activation button 140 is selectivelyactivatable in a first position and a second position to supplyelectrical energy from battery 300 to TAG 200 for operating instrument100 in a low-power mode of operation and a high-power mode of operation,respectively.

Referring to FIGS. 1-3, cooling inflow and return conduits 172, 174extend from cooling module 500, through housing 110, and at leastpartially through outer tube 154 of elongated body portion 150substantially along the length thereof. Proximal ends 173 a, 175 a ofinflow and return conduits 172, 174, respectively, are operably coupledto cooling module 500, as detailed below (see also FIG. 4).

With particular reference to FIG. 3, distal ends 173 b, 175 b of inflowand return conduits 172, 174, respectively, extend into waveguide 152.More specifically, a lumen 166 is formed within waveguide 152 thatextends through a portion of waveguide 152 including substantially alongthe length of blade 162 of waveguide. Lumen 166 defines a closed distalend. Conduits 172, 174 enter lumen 166 through an opening 168 definedwithin waveguide 152 and disposed in communication with lumen 166. Aseal (not shown) disposed within opening 168 and around inflow andreturn conduits 172, 174 is provided to inhibit the escape of fluidthereform. Inflow conduit 172 is disposed within and extends distallythrough lumen 166. Return conduit 174 is disposed within the proximalend of lumen 166, although the above-detailed configuration of inflowand return conduits 172, 174 may be reversed. Inflow conduit 172 has asmaller diameter than lumen 166 leaving an annular gap 169 therebetweento permit the return of fluid to return conduit 174. As such, duringcooling, fluid, e.g., water, saline, etc., is pumped through inflowconduit 172, exits a distal end of inflow conduit 172 at the distal endof lumen 166, and travels proximally back through lumen 166 withinannular gap 169, ultimately being received by return conduit 174 forreturn to cooling module 500 (FIG. 1). Inflow and return conduits 172,174 are at least partially formed from polyimide tubing. However, as ithas been found that the portion of inflow conduit 172 that extendsdistally through lumen 166 may be subject to delamination and, as aflow, may block the flow of fluid during use. As such, in embodiments,the portion of inflow conduit 172 that extends distally through lumen166 is formed from stainless steel or other material suitable towithstand high temperatures. Further, in embodiments where blade 162 iscurved, the portion of inflow conduit 172 that extends distally throughlumen 166 is likewise curved so as not to rub on the interior surface ofblade 162.

Referring to FIG. 4, cooling module 500 includes an input port 510, apump assembly 520, a controller 530, and a user interface 540. Inputport 510 enables operable coupling of cable 400 with cooling module 500.More specifically, input port 510 includes an inflow conduit receptacle512, a return conduit receptacle 514, and one or more electricalreceptacles 516. Inflow conduit receptacle 512 operably couples inflowconduit 172 with pump assembly 520 upon engagement of cable 400 withcooling module 500, return conduit receptacle 514 operably couplesreturn conduit 174 with pump assembly 520 upon engagement of cable 400with cooling module 500, and the electrical receptacles 516 operablycouple TAG 200 with controller 530, via wires 410, upon engagement ofcable 400 with cooling module 500. Inflow and return conduit receptacles512, 514 each include one or more sensors 513, 515, respectively,associated therewith for sensing the temperature of fluid flowingtherethrough, the flow rate of fluid therethrough, and/or the presenceof gas bubbles flowing therethrough, as detailed below.

Pump assembly 520 includes a fluid reservoir 522 and a pump 524 and iscoupled between inflow conduit 172 and return conduit 174. Fluidreservoir 522 stores fluid to be circulated through conduits 172, 174and lumen 166 to cool blade 162 of end effector assembly 160 (see FIG.3) after use. In some embodiments, fluid reservoir 522 may be configuredto regulate the temperature of the fluid retained therein. Further,instead of a closed system utilizing fluid reservoir 522, an open systemmay be provided wherein fluid to be circulated is received from anexternal fluid source (not shown), and fluid returning is output to adrain or return reservoir (not shown).

Pump 524 is configured as a pull-pump, wherein pump 524 operates to pullfluid through conduits 172, 174 and lumen 166. A pull-pump configurationis advantageous in that pressure build-up in push-pump configurations,e.g., due to an obstruction along the fluid flow path, is avoided.However, in some embodiments, pump 524 may be configured as a push-pump.Pump 524 may be a peristaltic pump, or any other suitable pump.

Continuing with reference to FIG. 4, controller 530 of cooling module500 includes a processor 532 and a memory 534 storing instructions forexecution by processor 532. Controller 530 is coupled to pump assembly520, sensors 513, 515, TAG 200 (via wires 410 extending through cable400), and user interface 540. Controller 530 may be configured toimplement the method of FIG. 10A or 10B so as to instruct pump assembly520 to turn pump 524 ON or OFF, to thereby initiate or stop bladecooling, based at least upon feedback received from sensors 513, 515,TAG 200, or other received feedback. As detailed below, controller 532may be configured so as to instruct pump assembly 520 to turn OFF pump524 where sensor 515 indicates a sufficiently low temperature of fluidreturning from return conduit 174. The temperature of blade 162 (FIG. 3)of end effector assembly 160 may be extrapolated from the temperature offluid returning from fluid conduit 174, or the temperature differencebetween the fluid entering inflow conduit 172 and that returning fromreturn conduit 174, and, accordingly, pump 524 may be turned OFF uponblade 162 reaching a sufficiently cool temperature, e.g., below about60° C. (or other suitable temperature threshold), as indicated by asufficiently low return fluid temperature or sufficiently smalltemperature differential. As an alternative to sensors 513, 515 sensingtemperature at input port 510, temperature sensors may be incorporatedinto pump assembly 520 for similar purposes as noted above. Further, inembodiments, a thermocouple 167 (FIG. 4) or other suitable temperaturesensor may additionally or alternatively be incorporated into blade 162(see, for example, thermocouple 2173 (FIG. 7)) to enable the sensing oftemperature at blade 162.

Controller 530, as also detailed below with respect to FIGS. 10A and10B, may additionally or alternatively instruct pump assembly 520 toturn OFF pump 524 or disable the entire system where sensor 513 and/orsensor 515 indicates an error. Such errors may include, for example,where sensor 513 and/or sensor 515 detects a flow rate through inflowconduit 172 and/or return conduit 174 below a threshold flow rate,and/or where sensor 515 detects gas bubbles, or a gas bubble volumegreater than a threshold volume, returning from return conduit 174.Reduced flow rate and/or the presence of gas bubbles (or a greatervolume of gas bubbles) may be an indication of a blockage or leak withinthe fluid flow path or damage to one of the conduits 172, 174 and, thus,the circulation of fluid is stopped by turning OFF pump 524 when such isdetected. As noted above, in embodiments, rather than just turning OFFpump 524, the entire system is disabled, thereby inhibiting further usepermanently or until the error or problem is remedied.

Controller 530 may further be configured, as also detailed below withrespect to FIGS. 10A and 10B, to output an appropriate signal to userinterface 540 and/or indicator 202 of TAG 200 to alert the user thatblade cooling is in effect, e.g., that pump 524 is ON, that an error,e.g., a blockage or leakage, has occurred, and/or that blade 162 (FIG.3) has been sufficiently cooled and is ready for further use. Userinterface 540 and/or indicator 202 may provide such an alert in the formof audible, visual, and/or tactile output.

Controller 530 may, additionally or alternatively, as also detailedbelow with respect to FIGS. 10A and 10B, be configured to communicatewith TAG 200 to determine whether endoscopic ultrasonic surgicalinstrument 100 is in use, e.g., whether activation button 140 isactuated such that ultrasonic energy is being supplied to blade 162 (seeFIG. 1), and to control pump assembly 520 in accordance therewith. Morespecifically, controller 530 may instruct pump assembly 520 to turn OFFpump 524 when endoscopic ultrasonic surgical instrument 100 is in use.Once use is complete, pump 524 may be turned ON for a pre-determinedtime, until blade 162 has been sufficiently cooled, until an error isdetected, or until endoscopic ultrasonic surgical instrument 100 is onceagain put into use.

Controller 530 may further communicate with TAG 200 to control thecooling system and/or determine whether the cooling system is operatingnormally based on the frequency of the transducer 210 and/or waveguide152 (FIG. 3). Thus, TAG 200 provides, e.g., via wires 410, the frequencyof the transducer 210 and/or waveguide 152 (FIG. 3) to the controller530. This frequency information is useful in that it is indicative ofthe state of the system. More specifically, it has been found thatduring use, e.g., during tissue treatment, the frequency decreases,while, upon deactivation and release of tissue, the frequency increases.It has further been found that, if waveguide 152 is cooled shortly afterdeactivation and release of tissue, the frequency increases at asignificantly greater rate as compared to an un-cooled waveguide 152.Thus by monitoring the rate of change in frequency, e.g., by monitoringdeviation of the rate of change relative to a threshold value orthreshold range, controller 530 can determine whether the cooling systemis working to effectively cool waveguide 152, or whether cooling isineffective or inoperable. Such may be used in addition to or in placeof temperature sensors. For example, the frequency information may beused, in conjunction with the flow rate information from sensors 513,515, to determine whether cooling is working properly, based upon theflow rates and frequency rate of change, without the need to directlymonitor temperature.

Turning now to FIG. 5, surgical system 20 is similar to surgical system10 (FIG. 1) and generally includes an endoscopic ultrasonic surgicalinstrument 1100 and a cooling module 1500. However, rather than beingcoupled via a cable 400 as with endoscopic ultrasonic surgicalinstrument 100 and cooling module 500 (FIG. 1), instrument 1100 includescooling module 1500 disposed thereon, e.g., formed as part of disposable1102 or releasably mounted thereon.

Instrument 1100 generally includes a disposable 1102, a transducer andgenerator assembly (“TAG”) 1200 including a transducer 1210 and agenerator 1220, and a battery 1300. Disposable 1102 includes a housing1110, a handle assembly 1120, a rotating assembly 1130, an activationbutton 1140, an elongated body portion 1150, and an end effectorassembly 1160, each of which are similar to the corresponding componentsof instrument 100 (FIG. 1), detailed above. TAG 1200 and battery 1300are releasably engagable with housing 1110 of disposable 1102 and, whenengaged therewith, are disposed in electrical communication with oneanother such that power and/or control signals can be relayed betweenTAG 1200 and battery 1300 for operating instrument 1100. TAG 1200 andbattery 1300 are similar to those detailed above with respect toinstrument 100 (FIG. 1), except as otherwise noted below.

Cooling module 1500, similar as with cooling module 500 (FIG. 4),includes input ports 1512, 1514, a pump assembly 1520, and a controller1530. Cooling module 1500 may be permanently mounted on TAG 1200, may bereleasably engagable with both TAG 1200 and disposable 1102, or may bepermanently mounted on or within disposable 1102. Input port 1512enables operable coupling of pump assembly 1520 with the conduits 1172,1174 of instrument 1100, while input port 1514 enables communicationbetween controller 1530 and generator 1220, both of which are similar asdetailed above with respect to input port 510 (FIG. 4). Pump assembly1520 and controller 1530 are also similar as detailed above, and may beconfigured to operate in a similar manner as mentioned above and asdescribed in greater detail below.

Turning now to FIGS. 6-9, another instrument provided in accordance withthe present disclosure, an open ultrasonic surgical instrument 2100, isdetailed. Open ultrasonic surgical instrument 2100 is configured tooperably coupled to a table-top generator (or other remote generator)(not shown) and a cooling module (similar to cooling module 500). Insome embodiments, the generator and cooling module are integrated into asingle housing (not shown). Open ultrasonic surgical instrument 2100generally includes two elongated shaft members 2110 a, 2110 b, anactivation button 2140, an elongated body portion 2150, an end effectorassembly 2160, a tube assembly 2170, and a transducer assembly 2200.

Referring to FIG. 6, each shaft member 2110 a, 2110 b includes a handle2111 a, 2111 b disposed at the proximal end 2112 a, 2112 b thereof. Eachhandle 2111 a, 2111 b defines a finger hole 2113 a, 2113 b therethroughfor receiving a finger of the user. One of the shaft members, e.g.,shaft member 2110 a, includes a jaw member 2164 of end effector assembly2160 extending from the distal end 2114 a thereof. The other shaftmember, e.g., shaft member 2110 b, supports elongated body portion 2150and transducer assembly 2200 thereon. Shaft members 2110 a, 2110 b arepivotably coupled to one another towards the distal ends 2114 a, 2114 b,respectively, thereof via a pivot pin 2118.

Elongated body portion 2150 of shaft member 2110 b includes a waveguide2152 (FIGS. 8A and 8B) which extends from transducer assembly 2200 toend effector assembly 2160, and an outer sleeve 2154 surroundingwaveguide 2152. The distal end of waveguide 2152 extends distally fromouter sleeve 2154 and defines a blade 2162 of end effector assembly2160, while the proximal end of waveguide 2152 is operably coupled totransducer assembly 2200. Due to the pivotable coupling of shaft members2110 a, 2110 b towards the distal ends 2114 a, 2114 b, respectively,thereof, handles 2111 a, 2111 b may be pivoted relative to one anotherto thereby pivot jaw member 2164 relative to blade 2162 between an openposition, wherein jaw member 2164 is spaced-apart from blade 2162, and aclosed position, wherein jaw member 2164 is approximated relative toblade 2162 in juxtaposed alignment therewith for clamping tissuetherebetween.

Transducer assembly 2200 is configured to convert electrical energyprovided by the generator (not shown) and supplied via cable 2210, intomechanical energy that is transmitted along waveguide 2152 to blade2162. Transducer assembly 2200 may be permanently affixed to elongatedbody portion 2150 or may be removable therefrom. Activation button 2140is disposed on one of the shaft members, e.g., shaft member 2110 b, and,similarly as detailed above with respect to instrument 100 (FIG. 1), isselectively activatable in a first position and a second position tosupply electrical energy to transducer assembly 2200 for operatinginstrument 2100 in a low-power mode of operation and a high-power modeof operation, respectively.

With reference to FIGS. 7 and 8A-8B, elongated body portion 2150 isdescribed in greater detail. As noted above, elongated body portion 2150includes waveguide 2152 and outer sleeve 2154. The distal end ofwaveguide 2152 extends distally from outer sleeve 2154 and defines blade2162. Waveguide is secured within outer sleeve 2154 via an O-ring 2156(FIGS. 8A and 8B). As shown in FIG. 7, blade 2162 defines a curvedconfiguration. Blade 2162 may be curved in any direction relative to jawmember 2164, for example, such that the distal tip of blade 2162 iscurved towards jaw member 2164, away from jaw member 2164, or laterally(in either direction) relative to jaw member 2164. Waveguide 2152 andblade 2162 may include any of the features of waveguide 152 and blade162 (see FIG. 3), and vice versa. Further, waveguide 2152 and blade 2162may be used with instrument 100 (FIG. 1), or any other suitableinstrument, and, likewise, waveguide 152 and blade 162 (see FIG. 3) maybe used with instrument 2100 (FIG. 6), or any other suitable instrument.

Referring again to FIGS. 7 and 8A-8B, waveguide 2152 defines a lumen2166 therethrough that extends into blade 2162. Lumen 2166 is open atits proximal end, the proximal end of waveguide 2152, and closed at itsdistal end, the closed distal end of blade 2162. Connection betweenwaveguide 2152 and transducer assembly 2200 at the proximal end ofwaveguide 2152 serves to close off the proximal end of lumen 2166 (seeFIG. 8A). Lumen 2166 defines a proximal segment 2167 a having the openproximal end and defining a first diameter, and a distal segment 2167 bhaving the closed distal end and defining a second diameter smaller thanthe first diameter.

Tube assembly 2170 (FIG. 6) includes inflow and return conduits 2172,2174, respectively, and a tube splitter 2176 (FIG. 9). Conduits 2172,2174 are arranged such that conduit 2174 is coaxially disposed aboutconduit 2172. Conduits 2172, 2174 enter proximal segment 2167 a of lumen2166, in the above-noted coaxial arrangement, through an opening 2168disposed in communication with lumen 2166. Inflow conduit 2172 extendsdistally from return conduit 2174 through proximal segment 2167 a oflumen 2166 into distal segment 2167 b of lumen 2166 to the distal end ofblade 2162. Inflow conduit 2172 has a smaller diameter than distalsegment 2167 b of lumen 2166 leaving an annular gap 2169 a therebetweento permit the return of fluid to return conduit 2174. Return conduit2174 does not extend into distal segment 2167 b of lumen 2166. Rather, aferrule 2175 is disposed about return conduit 2174 at the distal end ofproximal segment 2167 b of lumen 2166 so as to seal an annular gap 2169b of lumen 2166 surrounding return conduit 2174. As such, duringcooling, fluid is pumped through inflow conduit 2172, exits a distal endof inflow conduit 2172 at the distal end of lumen 2166, and travelsproximally back through lumen 2166 within annular gap 2169 a, ultimatelybeing received by return conduit 2174. Ferrule 2175 inhibits furtherproximal flow of cooling fluid, e.g., into annular gap 2169 b, thusensuring that the returning fluid enters return conduit 2174.

Referring to FIG. 9, tube splitter 2176 of tube assembly 2170 isdisposed within one of the shaft members, e.g., shaft member 2110 b, ofinstrument 2100 (see FIG. 6). Tube splitter 2176 receives the proximalends of conduits 2172, 2174 which, as noted above, are coaxiallydisposed relative to one another, and routes the flow of fluid to/fromconduits 2172, 2174 and respective connector tubes 2182, 2184. Connectortubes 2182, 2184, in turn, are coupled with a cooling module (not shown,similar to cooling module 500 (FIG. 1)) to enable the inflow and outflowof cooling fluid to/from conduits 2172, 2174, similarly as detailedabove with respect to instrument 100 (FIG. 1).

Tube splitter 2176 generally includes a housing 2190 defining a conduitport 2192, an interior chamber 2194, input and output ports 2196 a, 2196b, respectively, and an auxiliary port 2198. Conduit port 2192 receivesthe proximal ends of conduits 2172, 2174 which, as noted above, aredisposed in coaxial relation relative to one another. Return conduit2174 is sealingly engaged within conduit port 2192 so as to inhibit theescape of fluid therebetween. Return conduit 2174 terminates at interiorchamber 2194 and is disposed in fluid communication with interiorchamber 2194. Inflow conduit 2172 extends through interior chamber 2194and into input port 2196 a, wherein inflow conduit 2172 is sealinglyengaged. Connector tube 2182 is sealingly engaged about input port 2196a. Thus, fluid flowing through connector tube 2182 is routed into inflowconduit 2172 and, ultimately, through lumen 2166 (FIG. 7) of waveguide2152 and blade 2162 (FIG. 7). Connector tube 2184 is sealingly engagedabout output port 2196 b, which communicates with chamber 2194. As such,fluid flowing through return conduit 2174 ultimately flows into chamber2194 and, thereafter, out through output port 2196 b to connector tube2184. However, it is also contemplated that inflow and return conduits2172, 2174, respectively, be reversed, and, thus, that fluid flows inthe opposite direction. Auxiliary port 2198 communicates with chamber2194 and includes a stopper 2199 sealingly engaged therein.

Tube splitter 2176 further includes sensors 2197 a, 2197 b disposedadjacent input and output portion 2196 a, 2196 b, respectively, althoughsensors 2197 a 2197 b may be positioned at any suitable position on oralong instrument 2100 or the components thereof, e.g., the waveguide2152, blade 2162, inflow and return conduits 2172, 2174, transducerassembly 2200, etc. (see FIGS. 6-8B). Sensors 2197 a, 2197 b may beconfigured as thermocouples for sensing temperature and/or may otherwisebe configured similar to sensors 513, 515 (FIG. 4), respectively, to, asnoted above, sense the temperature of fluid flowing therethrough, theflow rate of fluid therethrough, and/or the presence of gas bubblesflowing therethrough.

Referring to FIGS. 1 and 9, although detailed above with respect toinstrument 2100 (FIG. 6), tube splitter 2176 and connector tubes 2182,2184 may similarly be used in connection with instrument 100, serving tocouple cooling module 500 and conduits 172, 174. In such aconfiguration, tube splitter 2176 is mounted within housing 110 ofdisposable 102 so as to receive the proximal ends of conduits 172, 174.Connector tubes 2182, 2184, in such a configuration, would extendthrough cable 400 for coupling with cooling module 500. Instrument 100would otherwise be configured similarly as detailed above and wouldfunction in a similar manner as detailed above and described in furtherdetail below.

Turning now to FIG. 10A, a method provided in accordance with thepresent disclosure, and applicable for use with instrument 100 (FIG. 1),instrument 1100 (FIG. 5), instrument 2100 (FIG. 6), or any othersuitable ultrasonic surgical instrument incorporating or configured foruse with a cooling system is described.

Initially, at S901, the end effector of the instrument is activated soas to supply ultrasonic energy to the end effector thereof to treat, forexample, coagulate and/or cut, tissue. At S902 it is determined whetherultrasonic energy is still being supplied to the end effector. Such adetermination may be performed, as noted above, by determining whetheran activation button is activated. However, other suitable ways ofdetermining whether ultrasonic energy is being supplied to the endeffector are also contemplated, e.g., monitoring the output of thebattery or the input to or output from the transducer. If it isdetermined that ultrasonic energy is being supplied, the determinationat S902 is repeatedly made, periodically or continuously, until it isdetermined that ultrasonic energy is no longer being supplied to the endeffector.

Once it is determined that ultrasonic energy is no longer being suppliedto the end effector, the cooling system is activated as indicated inS903, to circulate cooling fluid through the end effector to cool theend effector. Likewise, an indicator S904 is provided to indicate thatcooling is ongoing. During cooling, it is determined, at S905, whetherthe temperature of the end effector is below a threshold temperature. Asnoted above with respect to instrument 100 (FIG. 1), the temperature ofthe end effector may be determined indirectly by sensing the temperatureof the fluid output to the end effector and returning therefrom. Such aconfiguration enables the use of temperature sensors remote from the endeffector.

If the temperature of the end effector is determined to be above thethreshold temperature, cooling continues at S903 and the temperature iscontinuously or periodically determined at S905. At the same time, anindicator, as indicated in S904, is provided to alert the user thatcooling is still ongoing. Once the temperature of the end effectorassembly is below the threshold temperature, as indicated in S906,cooling is deactivated and the indicator is removed. The thresholdtemperature, in some embodiments, may be about 60° C.

Referring to S907, during cooling, if an error is detected, cooling isdeactivated at S906 and an indicator is provided at S904. Alternatively,the entire system may be shut down, inhibiting further activation oruse, as indicated at S906′. An error may include, as noted above, acondition where the flow rate of fluid is below a flow rate threshold, acondition where the fluid includes gas bubbles or a sufficiently highvolume of gas bubble, or other suitable error condition. The indicatorprovided in response to an error may be different from the indicatorprovided during cooling. If no error is detected, cooling continues atS903.

Turning to S908, during cooling, it is determined whether the supply ofultrasonic energy to the end effector has been activated. If so, coolingis deactivated at S909 and the method returns to S901. If the supplyingof ultrasonic energy to the end effector has not been activated, themethod returns to S903 and cooling is continued until the temperature ofthe end effector is below the threshold temperature, an error isdetected, or the supply of ultrasonic energy to the end effector isactivated.

Referring to FIG. 10B, another method provided in accordance with thepresent disclosure, and applicable for use with instrument 100 (FIG. 1),instrument 1100 (FIG. 5), instrument 2100 (FIG. 6), or any othersuitable ultrasonic surgical instrument incorporating or configured foruse with a cooling system is described.

The method of FIG. 10B is similar to that of FIG. 10A except that,during cooling, S913, it is determined at S914 whether the time coolinghas been activated has reached a threshold time. If the cooling time hasreached the threshold time, cooling is deactivated at S915. If thecooling time has not reached the threshold time, cooling continues atS913. Determination of the cooling time may be based upon anuninterrupted duration of cooling, a cumulative amount of cooling sincethe last energization of the end effector, or in any other suitablemanner.

Turning to FIG. 11, another surgical system for cooling a surgicalinstrument provided in accordance with the aspects and features of thepresent disclosure is shown generally identified by reference numeral3010. Surgical system 3010, as detailed below, is configured for usewith a conductive cooling fluid circulating through the instrument so asto enable measurement of the electrical impedance thereof to provide anindication of events that may occur during use, for example,determination of the whether the system is properly primed, detection ofmechanical failure, detection of obstruction(s) in the flowpath,detection of gas bubbles in the flowpath, determining whether cooling isoperating normally, etc. Surgical system 3010 may include any of thefeatures of the surgical systems detailed above, and vice-versa.Accordingly, only those distinguishing features and those necessary tofacilitate the understand of surgical system 3010 are described indetailed below.

Surgical system 3010 generally includes a surgical instrument 3100, acooling module 3500, and a cooling fluid flowpath 3600 definedtherebetween, e.g., via tubing, conduits, etc., that, together,incorporate a cooling system for cooling surgical instrument 3100.Surgical instrument 3100 may be configured similar to surgicalinstrument 100 (FIG. 1), surgical instrument 1100 (FIG. 5), surgicalinstrument 2100 (FIG. 6), or any other suitable surgical instrument.Inflow line 3610 of flowpath 3600 is configured to deliver conductivecooling fluid from cooling module 3500 to surgical instrument 3100,while outflow line 3620 of flowpath 3600 is configured to returnconductive cooling fluid from surgical instrument 3100 to cooling module3500.

Cooling module 3500 may be separate from surgical instrument 3100 (aswith cooling module 500 (FIG. 1)) or may be integrated into surgicalinstrument 3100 (as with cooling module 1500 (FIG. 5)). Cooling module3500 includes a generator 3510, a pump assembly 3520, a fluid reservoir3530 retaining a conductive cooling fluid therein, and a controller3540. Generator 3510 is electrically coupled to instrument 3100, e.g.,via one or more wires 3512, for supplying energy thereto. Whereinstrument 3100 is an ultrasonic instrument, for example, generator 3510supplies suitable energy to the transducer (not shown) of instrument3100 to drive the transducer. Generator 3510 further includes electrodes3514, 3516 that are disposed in communication with the conductivecooling fluid adjacent the output from cooling module 3500 to instrument3100 (location “A”) and towards the distal tip of instrument 3100(location “B”), respectively. Electrodes 3514, 3516 may extend throughinflow line 3610 and/or outflow line 3620 to respective locations “A”and “B,” as shown, may extend exteriorly of inflow line 3610 and/oroutflow line 3620 and electrically couple to the conductive coolingfluid by way of one or more conductive couplings (not shown) atrespective locations “A” and “B,” and/or may extend through a side wallof inflow line 3610 and/or outflow line 3620 into communication with theconductive cooling fluid at respective locations “A” and “B” with a sealdisposed thereabout for sealing the opening in the side wall of inflowline 3610 and/or outflow line 3620. Based upon electrical properties ofthe conductive cooling fluid detected by electrodes 3514, 3516,generator 3510 is capable of determining the impedance of the conductivecooling fluid between locations “A” and “B.” The determined impedancecan then be relayed to controller 3540 for outputting an indication ofvarious events and/or controlling system 3010 accordingly, as detailedbelow. Additional or alternative locations for determining impedancetherebetween are also contemplated, for example, the electrodes may bepositioned as detailed in any or all of the above systems with respectto the sensors thereof.

Pump assembly 3520 may include any suitable pump, such as those detailedabove, suitable for pumping conductive cooling fluid to circulate fromcooling module 3500, through instrument 3100, and back to cooling module3500. Controller 3540 may control pump assembly 3520 to turn the pump“ON” and “OFF,” to pump the conductive cooling fluid at a particularflow rate and/or to achieve a particular rate of cooling. Fluidreservoir 3530 may be, for example, an IV bag retaining saline (or othersuitable conductive cooling fluid) therein, or any other suitable fluidreservoir, such as those detailed above.

Referring still to FIG. 11, in use, as noted above, the determinedimpedance of the conductive cooling fluid between locations “A” and “B”can provide an indication of various events during use. For example,prior to cooling, system 3010 is primed by pump assembly 3520 operatingto pump conductive cooling fluid to fill flowpath 3600 and remove anyair bubbles from flowpath 3600. The impedance measurement can be used todetermine whether system 3010 has been properly primed, with all airbubbles removed. Specifically, this can be determined by comparing atarget “PRIMED” impedance (which may be stored in a memory of controller3540), representing the impedance in a condition where the cooling fluidflowpath 3600 is full, to the measured impedance between locations “A”and “B.” If there is a mismatch, difference outside an acceptable rangeof variability, or no impedance reading at all, this could indicate thatsystem 3010 has not been properly primed or that priming is not yetcomplete. In response, pump assembly 3520 may be further operated topump the conductive cooling fluid through flowpath 3600 to fill flowpath3600 and remove the air bubbles therefrom. Upon determining that thetarget “PRIMED” impedance has been achieved (or the measured impedanceis within the acceptable range of variability), the pump assembly 3520may be shut “OFF” and an indication provided that system 3010 is primedand ready for cooling.

In the same manner as above, the impedance measurement can be used toindicate whether there is an obstruction or leakage in the flowpath 3600and/or whether the surgical instrument is mechanically damaged, as suchwould result in a different impedance as compared to a correspondingtarget impedance, an impedance outside the acceptable range ofvariability as compared to a corresponding target impedance, or a “shortcircuit” condition, wherein an impedance measurement between locations“A” and “B” is unable to be obtained due to the lack of conductivecooling fluid extending therebetween. Based upon the impedancemeasurement and comparison, suitable indications may be provided toalert the user that there is an error or that an event that hasoccurred.

As another example, the impedance measurement may be utilized todetermine a cooled state, initiate cooling, deactivate cooling, controlcooling, and/or whether cooling is operating properly. This is becausethe impedance of the conductive cooling fluid will vary depending upontemperature. Thus, for example, controller 3540 can signal pump assembly3520 to begin pumping the conductive cooling fluid when a target “ON”impedance or impedance within a particular range has been reached and/orto stop pumping the conductive cooling fluid when a target “OFF”impedance or impedance within a particular range has been reached.Delays may also be built-in, for example, where pump assembly 3520 isturned “OFF” a pre-determined time after the target “OFF” impedance orimpedance within a particular range has been reached. Controller 3540may further direct pump assembly 3520 to increase or decrease the flowrate of the conductive cooling fluid, for example, based upon an initialimpedance at the beginning of cooling (indicative of the initialtemperature), a rate of change in impedance during cooling (indicativeof the efficiency of cooling), reaching certain intermediate impedancetargets (indicative of the efficiency of cooling), etc. A failure tocool or inefficient cooling can also be detected based upon theimpedance, indicating a lack of cooling or an unacceptable slow cooling.

The impedance-based feedback and control detailed above with respect tosurgical system 3010 may be used in conjunction with or in place of theother controls detailed hereinabove.

Referring to FIG. 11, in conjunction with FIGS. 1, 5, and 6, as notedabove, instruments 100, 1100, 2100 include activation buttons 140, 1140,2140 that are each selectively activatable in a first position and asecond position to supply electrical energy to operate the instrument100, 1100, 2100 in a low-power mode of operation and a high-power modeof operation, respectively. Such activation buttons 140, 1140, 2140,more specifically, are each coupled to corresponding circuitry thatprovide low-voltage activation signals in either a first state,indicating the low-power mode of operation, or a second state,indicating the high-power mode of operation, such that the appropriateamount of energy is supplied to operate the instrument 100, 1100, 2100in the selected mode.

Surgical instrument 3100 may include a similar activation button 3140 asdetailed above with respect to instruments 100, 1100, 2100, so as toprovide either a “low” or “high” power signal to generator 3510 (orother suitable component such as, for example, a battery that powersgenerator 3510) to activate surgical instrument 3100 in thecorresponding mode. In such a configuration, the electrodes 3514, 3516utilized to determine impedance, rather than being directly coupled togenerator 3510 (or the other suitable component), may be coupled to thecircuitry of activation button 3140 and utilize the connections betweenactivation button 3140 and generator 3510 (or the other suitablecomponent), to provide the electrical property measurements to generator3510 (or the other suitable component) without the need for additionalwiring extending between instrument 3100 and cooling module 3500 (orbetween the electrodes and the battery or generator, when instrument3100 employs an on-board battery and generator). As the “low” and “high”activation commands provided by activation button 3140 are at least anorder of magnitude different from the electrical property signals sensedby electrodes 3514, 3516 to determine impedance, utilizing the sameconnections does not interfere with the determination of whetheractivation button 3140 has been activated in either the “low” or “high”power modes.

While several embodiments of the disclosure have been shown in thedrawings and described hereinabove, it is not intended that thedisclosure be limited thereto, as it is intended that the disclosure beas broad in scope as the art will allow and that the specification beread likewise. Therefore, the above description should not be construedas limiting, but merely as exemplifications of particular embodiments.Those skilled in the art will envision other modifications within thescope and spirit of the claims appended hereto.

What is claimed is:
 1. A surgical system, comprising: a surgicalinstrument defining an input and an output; and a cooling moduleoperably coupled to the input and output of the surgical instrument, thecooling module including: a fluid reservoir retaining a conductivecooling fluid; a pump assembly operably coupled to the fluid reservoirand configured to pump the conductive cooling fluid along a flowpathfrom the fluid reservoir, into the input of the surgical instrument,through at least a portion of the surgical instrument, out the output ofthe surgical instrument, and back to the fluid reservoir; first andsecond electrodes disposed at an inflow position and an outflowposition, respectively, along the flowpath, the first and secondelectrodes configured to sense an electrical property of the conductivecooling fluid at the inflow and outflow positions; and a controllerconfigured to determine an impedance of the conductive cooling fluidbetween the inflow and outflow positions based upon the sensedelectrical properties of the first and second electrodes, wherein theoutflow position is disposed within or directly adjacent an end effectorof the surgical instrument, and wherein the inflow position is disposedwithin or directly adjacent the cooling module.
 2. The surgical systemaccording to claim 1, wherein the surgical instrument includes anultrasonic waveguide having a blade defined at a distal end thereof, andwherein the flowpath extends at least partially through the blade. 3.The surgical system according to claim 2, wherein the surgicalinstrument further includes an ultrasonic transducer coupled to theultrasonic waveguide and configured to energize the blade for treatingtissue therewith.
 4. The surgical system according to claim 1, furthercomprising a generator configured to supply energy to the surgicalinstrument.
 5. The surgical system according to claim 4, wherein thegenerator is disposed on the surgical instrument.
 6. The surgical systemaccording to claim 4, wherein the generator is spaced-apart from thesurgical instrument.
 7. The surgical system according to claim 4,wherein the surgical instrument further includes an activation buttonoperably coupled to the generator and including a first activatedposition and a second activated position for activating the surgicalinstrument in a first mode and a second mode, and wherein the first andsecond electrodes are operably coupled to the generator through theactivation button.
 8. The surgical system according to claim 1, whereinthe controller is configured to determine a temperature of the surgicalinstrument based upon the determined impedance.
 9. The surgical systemaccording to claim 1, wherein the controller is configured to determinewhether the flowpath has been properly primed with the conductivecooling fluid based upon the determined impedance.
 10. The surgicalsystem according to claim 1, wherein the controller is configured to atleast one of start or stop the pump assembly based upon the determinedimpedance.
 11. The surgical system according to claim 1, wherein thecontroller is configured to control the pump assembly based upon thedetermined impedance.
 12. The surgical system according to claim 1,wherein the controller is configured to determine the presences of atleast one of air bubbles, a blockage, or mechanical damage to thesurgical instrument based upon the determined impedance.
 13. Thesurgical system according to claim 1, wherein the cooling module isdisposed on the surgical instrument.
 14. The surgical system accordingto claim 1, wherein the cooling module is spaced-apart from the surgicalinstrument.